Such a sealing device has been disclosed in the following Patent Document 1 (JP-A-2001-65704) and Patent Document 2 (JP-A-2003-106464). The Patent Document 1 discloses a sealing device comprising a first sealing plate and a second sealing plate, one of them being a slinger, which have an L-shaped section and include a cylindrical wall and an upright wall (flange like portion) and a seal lip. The first and second sealing plates face each other, the tip end of the upright wall of the first sealing plate and the cylindrical wall of the second sealing plate stand face to face with a small radial gap (labyrinth), and the outer side face of the upright wall is set back inwardly from the end face of the cylindrical wall of the second sealing plate.
The Patent Document 2 discloses a sealing device in which the tip ends of the second dust lips (seal lip) elastically and slidably contacting with the inside of a metal ring (slinger) are disposed close so as to face each other, so that the deterioration of shrink range caused by abrasion and settling can be compensated, thereby preventing the ingress of dust into a closed space formed with two dust lips. Further, FIG. 1 of the Patent Document 2 shows an example wherein a part of the second seal portion contacts with the inside of the tip end portion of the outward flange (flange like portion) of the slinger.